The acceleration recorder of this invention is related to the field of collision dynamics and in particular to a recordation mechanism capable of detecting the magnitude of acceleration, in all three axes of a an orthogonal Cartesian coordinate system X, Y, and Z, that an object has been exposed to during an impact or collision.
Millions, if not billions, of dollars are paid out each year, in the United States alone, as a result of injuries due to accidents, crashes or collisions. A significant amount of this is due to fraudulent claims based on minor accidents or, in some instances, no accident at all. Conversely, many legitimate claims go unpaid because the injured are unable to verify the extent of the impact and their injuries. In view of this problem, attorneys typically retain professional engineers to perform forensic analyses using available techniques to determine the accelerations of a crash or collision. Thus, it is recognized that there is a need to be able to determine the accelerations a person, vehicle or other object has been subjected to in a collision. By having a means for recording and determining the severity of a collision, the evaluation of the resulting injuries could be more accurate and expedient.
At present, most serious accidents involving bodily injuries are subjected to extensive forensic analysis. By examining the physical evidence, such as skid marks, weight and geometry of the colliding vehicles, points of impact and rest, and the resultant damage of a collision, the approximate forces of an impact may be calculated. The calculated forces can then be utilized to calculate the approximate average accelerations the occupants experienced in the collision. The three-dimensional acceleration vector determines, to a great extent, the injuries to the occupants; however, these analyses are typically only in two dimensions.
The National Highways and Transportation Safety Administration (NHTSA) of the U. S. Department of Transportation has conducted numerous barrier tests to determine the stiffness properties of various types of vehicles. The weight of the vehicle, the speed at impact and the exact amount of resultant damage are recorded. Utilizing Newton""s Law of Motion and Hooke""s Spring Law, the impact forces and resultant stiffness properties are calculated. In future investigations of similar vehicles, the somewhat linear nature of vehicle stiffness allows investigators to approximate impact forces based on varying amounts of collision damage. These calculated forces could then be used in occupant acceleration calculations; however, the results only proximate the actual accelerations endured by the occupants.
Calculating head accelerations during athletic event impacts is even more challenging. Numerous sports involve the potential for significant head impacts during play; most notably among these sports is football. Repetitive head impacts involving high accelerations have been medically shown to cause permanent brain injury and death; however, no current method exists to determine the magnitude of each impact. In fact, unconsciousness is often used to differentiate between an acceptable and unacceptable impact. Unfortunately, the levels of force required to render an individual unconscious is often significantly higher than the forces required to injure the brain.
Now, there is no generally accepted small, light weight and inexpensive instrumentation that requires no batteries or external power and can be mounted on any vehicle or athletic protective gear, such as a helmet, to record the acceleration vector experienced by the participants of a collision or impact.
This invention is directed to providing an instrument that could be included as standard safety equipment on every vehicle and helmet.
Impact measuring devices are old in the art. For example, U.S. Pat. No. 5,551,279 describes a mechanical impact gauge for determining cumulative impact energy along a single axis using fixed bendable members within a chamber on either side of a freely movable object. Upon impact, the inertia of the movable object will cause the object to bend the fixed members. The amount of the bend can be used to calculate the force of impact.
When the device is aligned with the vector of the impact, the information derived is relatively accurate; however, if the impact vector is at an angle to the axis of the device, only the longitudinal portion of the vector is recorded and the gauge can become very inaccurate.
Of course, the xe2x80x9cblack boxesxe2x80x9d carried by some commercial aircraft and in the airplanes of all commercial air carriers give detailed information about an accident. These devices are relatively large, very expensive and most have a continuous power source. Such sophisticated instrumentation, and it""s cost, would place an undue burden on the price of individually owned vehicles and would be impossible to mount on a helmet.
Any moving object may be equipped with one or more acceleration recorders of this invention, such as boats, cars, trucks, buses, airplanes, motorcycles, or helmets. During a collision, the acceleration recorder gives empirical data concerning the vectored acceleration of the object to which the recorder is attached. The data can be used to reconstruct the direction and magnitude of any collision. When two or more recorders are used in conjunction rotational accelerations can also be derived.
Accordingly, it is an objective of the instant invention to provide an acceleration recorder that is inexpensive, small, lightweight and easy to permanently or removably mount on any vehicle or helmet. It is also an objective of this invention to provide an acceleration recorder that records acceleration in three orthogonal axes to provide a vector of the acceleration involved in a collision or impact.
It is a further objective of the instant invention to provide an acceleration recorder that may be tamper-proof or user inaccessible.
Other objects and advantages of this invention will become apparent from the following description taken in conjunction with the accompanying drawings wherein are set forth, by way of illustration and example, certain embodiments of this invention. The drawings constitute a part of this specification and include exemplary embodiments of the present invention and illustrate various objects and features thereof.